Multiple types of mobile sensing platforms, including aircraft, marine vessels, and vehicle-mounted or vehicle-towed systems, make use of phased array antennas for remote sensing and communication. Modern active electrically scanned array (“AESA”) systems typically use multiple isolated radio-frequency, control signal, and power transmission lines to distribute primary high frequency (microwave or “RF”) signals, secondary low frequency control signals, and DC power to the individual antenna elements of an array. The need for multiple isolated transmission lines or “manifolds” is typically met by providing different conductive paths which occupy different footprints in a common plane or layer, by providing different conductive paths which share a common footprint in different planes or layers (typically separated by a layer of metalized dielectric material), or by a combination of these features. The use of separate manifolds is a significant factor affecting the weight and profile of current AESA technology. If the weight and size, particularly the profile or thickness, of an AESA system could be reduced, such systems could be more readily employed on payload limited sensing platforms such as unmanned aerial vehicles (“UAVs”), as well as in improved versions of existing sensing platforms. The multi-conductor transmission line structures disclosed herein may be used to substantially replace the separate manifolds described above, as well as to improve wireless communications systems employing a combination of high frequency RF energy for distant communications, low frequency energy for internal signaling and/or control, and DC power distribution for the powering of constituent subsystems.